1 files changed, 41 insertions, 15 deletions

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index ac16a9db1fb5..1c4d7b4e4fb5 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -470,17 +470,36 @@ static void pmu_read_sysfs(void)
         closedir(dir);
 }
 
+static struct cpu_map *__pmu_cpumask(const char *path)
+{
+        FILE *file;
+        struct cpu_map *cpus;
+
+        file = fopen(path, "r");
+        if (!file)
+                return NULL;
+
+        cpus = cpu_map__read(file);
+        fclose(file);
+        return cpus;
+}
+
+/*
+ * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
+ * may have a "cpus" file.
+ */
+#define CPUS_TEMPLATE_UNCORE    "%s/bus/event_source/devices/%s/cpumask"
+#define CPUS_TEMPLATE_CPU       "%s/bus/event_source/devices/%s/cpus"
+
 static struct cpu_map *pmu_cpumask(const char *name)
 {
-        struct stat st;
         char path[PATH_MAX];
-        FILE *file;
         struct cpu_map *cpus;
         const char *sysfs = sysfs__mountpoint();
         const char *templates[] = {
-                 "%s/bus/event_source/devices/%s/cpumask",
-                 "%s/bus/event_source/devices/%s/cpus",
-                 NULL
+                CPUS_TEMPLATE_UNCORE,
+                CPUS_TEMPLATE_CPU,
+                NULL
         };
         const char **template;
 
@@ -489,20 +508,25 @@ static struct cpu_map *pmu_cpumask(const char *name)
 
         for (template = templates; *template; template++) {
                 snprintf(path, PATH_MAX, *template, sysfs, name);
-                if (stat(path, &st) == 0)
-                        break;
+                cpus = __pmu_cpumask(path);
+                if (cpus)
+                        return cpus;
         }
 
-        if (!*template)
-                return NULL;
+        return NULL;
+}
 
-        file = fopen(path, "r");
-        if (!file)
-                return NULL;
+static bool pmu_is_uncore(const char *name)
+{
+        char path[PATH_MAX];
+        struct cpu_map *cpus;
+        const char *sysfs = sysfs__mountpoint();
 
-        cpus = cpu_map__read(file);
-        fclose(file);
-        return cpus;
+        snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
+        cpus = __pmu_cpumask(path);
+        cpu_map__put(cpus);
+
+        return !!cpus;
 }
 
 /*
@@ -617,6 +641,8 @@ static struct perf_pmu *pmu_lookup(const char *name)
 
         pmu->cpus = pmu_cpumask(name);
 
+        pmu->is_uncore = pmu_is_uncore(name);
+
         INIT_LIST_HEAD(&pmu->format);
         INIT_LIST_HEAD(&pmu->aliases);
         list_splice(&format, &pmu->format);